Pressure sensitive adhesive composition, pressure sensitive adhesive film, and method of manufacturing organic electronic device using the same

ABSTRACT

Provided are a pressure-sensitive adhesive composition, a pressure-sensitive adhesive film, and a method of manufacturing an organic electronic device using the same. The pressure-sensitive adhesive composition that may effectively prevent moisture or oxygen added to an organic electronic device from an external environment, and exhibit reliability under harsh conditions such as high temperature and high humidity and excellent optical characteristics, and a pressure-sensitive adhesive film including the same are provided.

BACKGROUND

1. Field of the Invention

The present invention relates to a pressure-sensitive adhesivecomposition, a pressure-sensitive adhesive film, and a method ofmanufacturing an organic electronic device using the same.

2. Discussion of Related Art

An organic electronic device (OED) refers to a device including anorganic material layer generating alternation of charges using holes andelectrons, and may include, for example, a photovoltaic device, arectifier, a transmitter, and an organic light emitting diode (OLED).

A representative OED, which is an OLED, has less power consumption and ahigher response speed, and forms a thinner display device or light thana conventional light source. In addition, the OLED has excellent spaceutilization, and is expected to be applied in various fields includingall kinds of portable devices, monitors, notebook computers, and TVs.

To extend commercialization and use of the OLED, a major problem isdurability. Organic materials and metal electrodes included in the OLEDare very easily oxidized by external factors such as water, and aproduct including the OLED is very sensitive to environmental factors.Therefore, various methods to prevent penetration of oxygen or waterfrom an external environment with respect to an organic electronicdevice such as the OLED have been suggested.

In Korean Unexamined Patent No. 2008-0088606, an adhesive capsulatedcomposition film and an organic electroluminescence light emittingdevice are provided, and have poor processability as apressure-sensitive adhesive based on polyisobutylene (PIB) and lowreliability under conditions of high temperature and high humidity.

Accordingly, in an organic electronic device, it is required to developan encapsulant ensuring a required lifetime, excellently preventingpermeation of moisture, maintaining reliability under conditions of hightemperature and high humidity, and having excellent opticalcharacteristics.

SUMMARY OF THE INVENTION

The present invention is directed to providing a pressure-sensitiveadhesive composition which can form a structure effectively preventingmoisture or oxygen input to an organic electronic device from anexternal environment, and has excellent mechanical characteristics suchas handleability and processability and excellent transparency, apressure-sensitive adhesive film, and a method of manufacturing anorganic electronic device using the same.

In one aspect, the present invention provides a pressure-sensitiveadhesive composition. The pressure-sensitive adhesive composition may beapplied to, for example, encapsulation or capsulation of an organicelectronic device such as an OLED.

The term “organic electronic device” used herein refers to a product ordevice having a structure including an organic material layer generatingalternation of charges using holes and electrons between a pair ofelectrodes facing each other, and may include, but is not limited to,for example, a photovoltaic device, a rectifier, a transmitter, and anorganic light emitting diode (OLED). In one example, the organicelectronic device may be an OLED.

In an exemplary embodiment of the present invention, thepressure-sensitive adhesive composition may include an encapsulatingresin including a copolymer of a diene and an olefin-based compoundhaving one carbon-carbon double bond, and a multifunctional activeenergy ray-polymerizable compound that can be polymerized by irradiationof an active energy ray. The active energy ray-polymerizable compoundmay satisfy Formula 1:

In Formula 1, R₁ is hydrogen or an alkyl group having 1 to 4 carbonatoms, n is an integer of 2 or more, and X is a residue induced from alinear, branched, or cyclic alkyl group having 3 to 30 carbon atoms.

In one example, the pressure-sensitive adhesive composition of thepresent invention may have an excellent light transmittance and a lowhaze when being prepared in a film. In one example, thepressure-sensitive adhesive composition may have a haze of 3%, 2.8%,2.5%, 2.3%, 2.2%, or 2.0% or less when being prepared in a film. Thatis, the pressure-sensitive adhesive composition of the present inventionmay have a specific crosslinking structure, thereby exhibitingreliability under conditions of high temperature and high humidity, andmay use an active energy ray-polymerizable compound having an excellentcompatibility with the encapsulating resin and other additives to reducea haze caused by a reaction, thereby exhibiting excellent opticalcharacteristics.

In an exemplary embodiment of the present invention, the encapsulatingresin may have a glass transition temperature of less than 0, −10, −30,−50, or −60° C. Here, the glass transition temperature may refer to aglass transition temperature after UV rays are irradiated at a dose ofapproximately 1 J/cm² or more, or a glass transition temperature afterthermal curing is additionally performed after UV irradiation.

In one example, the encapsulating resin may include a styrene-basedresin or an elastomer, a polyolefin-based resin or an elastomer, otherelastomers, a polyoxyalkylene-based resin or an elastomer, apolyester-based resin or an elastomer, a polyvinylchloride-based resinor an elastomer, a polycarbonate-based resin or an elastomer, apolyphenylenesulfide-based resin or an elastomer, a mixture ofhydrocarbon, a polyamide-based resin or an elastomer, an acrylate-basedresin or an elastomer, an epoxy-based resin or an elastomer, asilicon-based resin or an elastomer, a fluorine-based resin or anelastomer, or a mixture thereof.

Here, the styrene-based resin or an elastomer may be, for example, a astyrene-ethylene-butadiene-styrene (SEBS) block copolymer, astyrene-isoprene-styrene (SIS) block copolymer, anacrylonitrile-butadiene-styrene (ABS) block copolymer, anacrylonitrile-styrene-acrylate (ASA) block copolymer, astyrene-butadiene-styrene (SBS) block copolymer, a styrene-basedhomocopolymer, or a mixture thereof. The olefin-based resin or anelastomer may be, for example, a high density polyethylene-based resinor an elastomer, a low density polyethylene-based resin or an elastomer,a polypropylene-based resin or an elastomer, or a mixture thereof. Theelastomer may be, for example, an ester-based thermoplastic elastomer,an olefin-based elastomer, a silicon-based elastomer, an acrylicelastomer, or a mixture thereof. Among these, the olefin-basedthermoplastic elastomer may be a polybutadiene resin or an elastomer ora polyisobutylene resin or an elastomer. The polyoxyalkylene-based resinor an elastomer may be, for example, a polyoxymethylene-based resin oran elastomer, a polyoxyethylene-based resin or an elastomer, or amixture thereof. The polyester-based resin or an elastomer may be, forexample, a polyethylene terephthalate-based resin or an elastomer, apolybutylene terephthalate-based resin or an elastomer, or a mixturethereof. The polyvinylchloride-based resin or an elastomer may be, forexample, polyvinylidene chloride. The mixture of hydrocarbon may be, forexample, hexatriacontane or paraffin. The polyamide-based resin or anelastomer may be, for example, nylon. The acrylate-based resin or anelastomer may be, for example, polybutyl(meth)acrylate. The epoxy-basedresin or an elastomer may be, for example, a bisphenol-type such as abisphenol A-type, a bisphenol F-type, a bisphenol S-type, and ahydrogenated product thereof; a novolac-type such as aphenolnovolac-type or a cresolnovolac-type; a nitrogen-containingring-type such as a triglycidylisocyanurate-type or a hydantoin-type; analicyclic-type; an aliphatic-type; an aromatic-type such as anaphthalene-type or a biphenyl-type; a glycidyl-type such as aglycidylether-type, a glycidylamine-type, or a glycidylester-type; adicyclo-type such as dicyclopentadiene-type; an ester-type; anetherester-type; or a mixture thereof. The silicon-based resin or anelastomer may be, for example, polydimethylsiloxane. In addition, thefluorine-based resin or an elastomer may be a polytrifluoroethyleneresin or an elastomer, a polytetrafluoroethylene resin or an elastomer,a polychlorotrifluoroethylene resin or an elastomer, apolyhexafluoropropylene resin or an elastomer, polyvinylidene fluoride,polyvinyl fluoride, polyethylenepropylene fluoride, or a mixturethereof.

One of the above-listed resins or elastomers may be grafted to, forexample, maleic anhydride, copolymerized with another one of the listedresins or elastomers or a monomer for preparing the resin or elastomer,or modified by a compound, other than the above-used resins orelastomers. The compound may be a carboxyl-terminatedbutadiene-acrylonitrile copolymer.

In one example, the pressure-sensitive adhesive composition is anencapsulating resin, which may include an olefin-based elastomer, asilicon-based elastomer, or an acrylic elastomer of the above-describedtypes, but the present invention is not limited thereto.

Particularly, the encapsulating resin may be a copolymer of a diene andan olefin-based compound having one carbon-carbon double bond. Here, theolefin-based compound may include isobutylene, propylene, or ethylene,and the diene may be a monomer capable of being polymerized with theolefin-based compound, for example, 1-butene, 2-butene, isoprene, orbutadiene. That is, the encapsulating resin of the present invention maybe, for example, a homopolymer of an isobutylene monomer; a copolymerprepared by copolymerizing an isobutylene monomer with a monomer capableof being polymerized therewith; or a mixture thereof. In one example,the copolymer of the olefin-based compound having one carbon-carbondouble bond and the diene may be a butyl rubber. When a specific resinis used as described above, moisture barrierability that would beachieved in the present invention may be satisfied. In addition, thepresent invention may improve humidity resistance and heat resistance bypreparing a specific composition satisfying Equation 1 described abovedue to low heat resistance, while a conventional isobutylene polymer haslow moisture permeability.

In the pressure-sensitive adhesive composition, the resin or elastomercomponent may have a weight average molecular weight (Mw) to an extentthat the pressure-sensitive adhesive composition can be plasticized in afilm type. For example, the resin or elastomer may have a weight averagemolecular weight (Mw) of approximately 100,000 to 2,000,000, 100,000 to1,500,000, or 100,000 to 1,000,000. The term “weight average molecularweight” used herein refers to a converted value with respect to standardpolystyrene measured by gel permeation chromatography (GPC). However,the resin or elastomer component does not necessarily have theabove-mentioned weight average molecular weight. For example, when amolecular weight of the resin or elastomer component is not sufficientfor forming a film, a separate binder resin may be blended in thepressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition of the present invention mayinclude, as described above, an active energy ray-polymerizablecompound, which has a high compatibility with the encapsulating resin,and form a specific crosslinking structure along with the encapsulatingresin. That is, the active energy ray-polymerizable compound satisfyingFormula 1 may particularly have an excellent compatibility with theencapsulating resin of the present invention, and thus satisfy anoptical characteristic and reliability at high temperature and highhumidity. For example, the active energy ray-polymerizable compound mayrealize a pressure-sensitive adhesive composition having an excellentmoisture barrierability, high reliability at high temperature and highhumidity, and excellent optical characteristics such as lighttransmittance and haze along with the above-described diene andolefin-based compound having one carbon-carbon double bond.

The pressure-sensitive adhesive composition of the present invention, asdescribed above, may include an active energy ray-polymerizable compoundhaving a high compatibility with an encapsulating resin, and forming aspecific crosslinking structure along with the encapsulating resin. Thatis, the active energy ray-polymerizable compound satisfying Formula 1may particularly have an excellent compatibility with the encapsulatingresin of the present invention to satisfy optical characteristics andreliability at high temperature and high humidity. For example, theactive energy ray-polymerizable compound may realize apressure-sensitive adhesive composition having an excellent moisturebarrierability, excellent reliability at high temperature and highhumidity, and excellent optical characteristics such as lighttransmittance and a haze along with the above-described copolymer of adiene and an olefin-based compound having one carbon-carbon double bond.

The active energy ray-polymerizable compound may refer to, for example,a compound including at least two of functional groups that canparticipate in a polymerization reaction by irradiation of an activeenergy ray, for example, a functional group including an ethylene-likeunsaturated double bond such as an acryloyl group or a methacryloylgroup, and a functional group such as an epoxy group or an oxetanegroup.

As described above, the active energy ray-polymerizable compound maysatisfy Formula 1:

In Formula 1, R₁ is hydrogen or an alkyl group having 1 to 4 carbonatoms, n is an integer of 2 or more, and X is a residue induced from alinear, branched, or cyclic alkyl group having 3 to 30 carbon atoms.Here, when X is a residue induced from a cyclic alkyl group, X may be aresidue induced from a cyclic alkyl group having 3 to 30, 6 to 28, 8 to22, or 12 to 20 carbon atoms. In addition, when X is a residue inducedfrom a linear alkyl group, X may be a residue induced from a linearalkyl group having 3 to 30, 6 to 25, or 8 to 20 carbon atoms. Inaddition, when X is a residue induced from a branched alkyl group, X maybe a residue induced from a branched alkyl group having 3 to 30, 5 to25, or 6 to 20 carbon atoms.

The term “residue induced from an alkyl group” used herein may refer toa residue of a specific compound, which is formed of an alkyl group. Inone example, in Formula 1, when n is 2, X may be an alkylene group. Inaddition, when n is 3 or more, at least two hydrogens of an alkyl groupare released and bind to a (meth)acryloyl group of Formula 1.

The term “alkyl group” used herein may be, unless particularly definedotherwise, an alkyl group having 1 to 30, 1 to 25, 1 to 20, 1 to 16, 1to 12, 1 to 8, or 1 to 4 carbon atoms. The alkyl group may have alinear, branched, or cyclic structure, and may be optionally substitutedby at least one substituent.

The term “alkylene group” used herein may be, unless particularlydefined otherwise, an alkylene group having 2 to 30, 2 to 25, 2 to 20, 2to 16, 2 to 12, 2 to 10, or 2 to 8 carbon atoms. The alkylene group mayhave a linear, branched, or cyclic structure, and may be optionallysubstituted by at least one substituent.

The active energy ray-polymerizable compound may be included at 5 to 30,5 to 25, 8 to 20, 10 to 18, or 12 to 18 parts by weight relative to 100parts by weight of the encapsulating resin.

A multifunctional active energy ray-polymerizable compound that can bepolymerized by the irradiation of an active energy ray may be usedwithout limitation as long as satisfying Formula 1. For example, thecompound may be 1,4-butanediol di(meth)acrylate, 1,3-butylene glycoldi(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanedioldi(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, neopentylglycoldi(meth)acrylate, dicyclopentanyl di(meth)acrylate,cyclohexane-1,4-dimethanol di(meth)acrylate, tricyclodecanedimethanol(meth)diacrylate, dimethylol dicyclopentane di(meth)acrylate,neopentylglycol modified trimethylpropane di(meth)acrylate, adamantanedi(meth)acrylate, trimethylolpropane tri(meth)acrylate, or a mixturethereof.

As the multifunctional active energy ray-polymerizable compound, forexample, a compound having a molecular weight of less than 1,000 andincluding at least two functional groups may be used. In this case, themolecular weight may refer to a weight average molecular weight or aconventional molecular weight. A cyclic structure included in themultifunctional active energy ray-polymerizable compound may be any oneof a carbocyclic structure, a heterocyclic structure, a monocyclicstructure, and a polycyclic structure.

In addition, in an exemplary embodiment of the present invention, thepressure-sensitive adhesive composition may further include a silanecompound satisfying Formula 2:

In Formula 2, R₁ is hydrogen or an alkyl group. R₁ may be, for example,an alkyl group having 1 to 4 or 1 to 2 carbon atoms. In addition, inFormula 2, R₂ and R₃ are each independently hydrogen, or a linear,branched, or cyclic alkyl group, or when R₂ is linked with R₃, a cyclicalkyl group may be formed. For example, R₂ and R₃ may be eachindependently hydrogen, or a linear, branched, or cyclic alkyl group.Here, the linear alkyl group may have 1 to 10, 1 to 6, or 1 to 4 carbonatoms, the branched alkyl group may have 3 to 10, 3 to 6, or 3 to 4carbon atoms, and the cyclic alkyl group may have 3 to 10, 3 to 8, 3 to6, or 3 to 4 carbon atoms.

In addition, when R₂ is linked with R₃, a cyclic alkyl group having 2 to10, 3 to 10, 4 to 9, or 4 to 8 carbon atoms may be formed. In addition,in Formula 1, R₄, R₅, and R₆ may each independently hydrogen, an alkylgroup, or an alkoxy group, at least one of R₄, R₅, and R₆ is an alkoxygroup, and n is an integer of 1 or more. Specifically, the R₄, R₅, andR₆ may be each independently an alkyl group having 1 to 10, 1 to 6, 1 to4, or 1 to 2 carbon atoms; or an alkoxy group having 1 to 10, 1 to 8, 1to 4, or 1 to 2 carbon atoms. Here, at least one of R₄, R₅, and R₆ maybe an alkoxy group, and all of R₄, R₅, and R₆ may be alkoxy groups, butthe present invention is not limited thereto.

The term “alkoxy group” used herein may be, unless particularly definedotherwise, an alkoxy group having 1 to 20, 1 to 16, 1 to 12, 1 to 8, or1 to 4 carbon atoms. The alkoxy group may be a linear, branched, orcyclic type. In addition, the alkoxy group may be optionally substitutedby at least one substituent.

In one example, the silane compound may be, for example,3-methacryloxypropyl trimethoxysilane, 3-methacryloxy propyltriethoxysilane, 3-acryloxy propyl trimethoxysilane, 3-acryloxy propyltriethoxysilane, 3-methacryloxy methyl triethoxysilane, 3-methacryloxymethyl trimethoxysilane, 3-acryloxy propyl methyldimethoxysilane,methacryloxy methyl methyldimethoxysilane, methacryloxy methylmethyldiethoxysilane, methacryloxy propyl methyldimethoxysilane,methacryloxy propyl methyldiethoxysilane, methacryloxy propyldimethylmethoxysilane, or methacryloxy propyl dimethylethoxysilane. Anacryl group of the silane compound may serve to increase an interfacepressure-sensitive adhesive strength by being crosslinked with theencapsulating resin or active energy ray-polymerizable compound of thepressure-sensitive adhesive composition. The silane compound may beincluded at 0.1 to 10, 0.5 to 8, 0.8 to 5, 1 to 5, 1 to 4.5, or 1 to 4parts by weight relative to 100 parts by weight of the encapsulatingresin.

In one example, the active energy ray-polymerizable compound may form acrosslinking structure with the silane compound satisfying Formula 2,and the crosslinking structure may form a semi-interpenetrating polymernetwork (semi-PIN) with the encapsulating resin. That is, thepressure-sensitive adhesive composition may include a semi-IPN. The term“semi-IPN” includes at least one polymer crosslinking structure (polymernetwork) and at least one linear or branched polymer, and at least apart of the linear or branched polymer has a structure penetrated intothe polymer crosslinking structure. The semi-IPN may be distinguishedfrom an IPN structure since the linear or branched polymer can betheoretically separated from the polymer crosslinking structure withoutloss of a chemical bond.

In one exemplary embodiment, the crosslinking structure may be acrosslinking structure formed by application of heat, a crosslinkingstructure formed by irradiation of an active energy ray, or acrosslinking structure formed by aging at room temperature. Here, in thecategory of the “active energy ray”, a microwave, an infrared (IR) ray,an ultraviolet (UV) ray, an X ray and a gamma ray, and a particle beamsuch as an alpha-particle beam, a proton beam, a neutron beam, or anelectron beam, and conventionally, an UV ray and an electron beam may beincluded. As such a semi-IPN structure is introduced, a mechanicalproperty such as processability of the pressure-sensitive adhesivecomposition may be increased, humidity-resistant adhesive performance isimproved, transparency is realized, high moisture barrier performancethat cannot be achieved so far, and an excellent panel lifetime may berealized.

In one example, the active energy ray-polymerizable compound may form acrosslinking structure with the silane compound satisfying Formula 2,and the encapsulating resin may form a crosslinking structure with theactive energy ray-polymerizable compound or the silane compoundsatisfying Formula 2, thereby forming an interpenetrating polymernetwork (IPN) structure. In addition, the term “IPN structure” refers toa state in which at least two crosslinking structures are present in apressure-sensitive adhesive. In one example, the IPN structure may referto a structure including at least two crosslinking structures in anintertwining, entanglement, or penetrating state. For example, thecomposition of the present invention may include a crosslinkingstructure by an encapsulating resin (hereinafter, referred to as a“first crosslinking structure”) and a crosslinking structure formed by areaction of an active energy ray-polymerizable compound and the silanecompound satisfying Formula 2 (hereinafter, referred to as a “secondcrosslinking structure”), and the first and second crosslinkingstructures may be in an interwinding state or an entanglement state.That is, when the pressure-sensitive adhesive composition includes asemi-IPN or IPN structure in a crosslinked state, excellent durabilityand reliability of a pressure-sensitive adhesive may be realized underharsh conditions such as high temperature and high humidity.

In an exemplary embodiment of the present invention, thepressure-sensitive adhesive composition may further include a radicalinitiator that can induce a polymerization reaction of theabove-described active energy ray-polymerizable compound. The radicalinitiator may be a photoinitiator or a thermal initiator. A specifictype of the photoinitiator maybe suitably selected in consideration of acuring rate and yellowing probability. For example, as thephotoinitiator, a benzoin-, hydroxy ketone-, amino ketone-, or phosphineoxide-based photoinitiator, and specifically, benzoin, benzoinmethylether, benzoin ethylether, benzoin isopropylether, benzoinn-butylether, benzoin isobutylether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone,2,2-diethoxy-2-phenylacetophenone,2-hydroxy-2-methyl-1-phenylpropane-1one,1-hydroxycyclohexylphenylketone,2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propane-1-one,4-(2-hydroxyethoxyl)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone,p-phenylbenzophenone, 4,4′-diethylaminobenzophenone,dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone,2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone,2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone,2,4-diethylthioxanthone, benzyldimethylketal, acetophenonedimethylketal, p-dimethylamino benzoic acid ester,oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone], or2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide may be used.

The radical initiator may be included at 0.2 to 20, 0.5 to 18, 1 to 15,or 2 to 13 parts by weight relative to 100 parts by weight of the activeenergy ray-polymerizable compound. Accordingly, the reaction of theactive energy ray-polymerizable compound is effectively induced, anddegradation of physical properties of the pressure-sensitive adhesivecomposition due to remaining components after curing may be prevented.

In one example, the pressure-sensitive adhesive composition may furtherinclude a tackifier. The tackifier may be a hydrogenated cyclicolefin-based polymer. As the tackifier, for example, a hydrogenatedpetroleum resin obtained by hydrogenating a petroleum resin may be used.The hydrogenated petroleum resin may be partially or completelyhydrogenated, and may be a mixture of such resins. Such a tackifier mayhave a high compatibility with the pressure-sensitive adhesivecomposition, excellent moisture barrierability, and a small content ofan organic volatile component. A specific example of the hydrogenatedpetroleum resin may be a hydrogenated terpene-based resin, ahydrogenated ester-based resin, or a hydrogenateddicyclopentadiene-based resin. The tackifier may have a weight averagemolecular weight of approximately 200 to 5,000. A content of thetackifier may be suitably controlled as needed. For example, the contentof the tackifier may be selected in consideration of a gel content thatwill be described below or compatibility with the encapsulating resin.According to one example, the tackifier may be included at 5 to 100, 8to 95, 10 to 93, or 15 to 90 parts by weight relative to 100 parts byweight of a solid content of the pressure-sensitive adhesivecomposition.

The pressure-sensitive adhesive composition may further include amoisture absorbent when needed. The term “moisture absorbent” may referto a material that can remove moisture or vapor penetrated into thefollowing pressure-sensitive adhesive film through a chemical reaction.When the pressure-sensitive adhesive composition of the presentinvention includes a moisture absorbent, to be formed in a film, thefollowing light transmittance may not be realized, but excellentmoisture barrier ability may be realized. Specifically, thepressure-sensitive adhesive composition may be formed in a film to beapplied to encapsulation of an organic electronic device. In this case,when the pressure-sensitive adhesive composition does not include amoisture absorbent and exhibits excellent transparency, it may beapplied to encapsulation of a top-emissive organic electronic device, orwhen the pressure-sensitive adhesive composition includes a moistureabsorbent and exhibit excellent moisture barrierability, it may beapplied to encapsulation of a bottom-emissive organic electronic device.However, the present invention is not limited thereto. That is, when thepressure-sensitive adhesive composition does not include a moistureabsorbent and exhibits excellent transparency, it may be applied toencapsulation of a bottom-emissive organic electronic device.

For example, the moisture absorbent may be present while being uniformlydispersed in the pressure-sensitive adhesive composition or thefollowing pressure-sensitive adhesive layer. Here, the uniformlydispersed state may mean a state in which the moisture absorbent ispresent even in any part of the pressure-sensitive adhesive compositionor the pressure-sensitive adhesive layer at the same or substantiallythe same density. As the moisture absorbent used herein, for example, ametal oxide, a sulfate, or an organic metal oxide may be used.Specifically, the sulfate may be magnesium sulfate, sodium sulfate, ornickel sulfate, and the organic metal oxide may be aluminum oxideoctylate. Here, the metal oxide may be phosphorus pentoxide (P₂O₅),lithium oxide (Li₂O), sodium oxide (Na₂O), barium oxide (BaO), calciumoxide (CaO), or magnesium oxide (MgO), and the metal salt may be asulfate such as lithium sulfate (Li₂SO₄), sodium sulfate (Na₂SO₄),calcium sulfate (CaSO₄), magnesium sulfate (MgSO₄), cobalt sulfate(CoSO₄), gallium sulfate (Ga₂(SO₄)₃), titanium sulfate (Ti(SO₄)₂), ornickel sulfate (NiSO₄); a metal halide such as calcium chloride (CaCl₂),magnesium chloride (MgCl₂), strontium chloride (SrCl₂), yttrium chloride(YCl₃), copper chloride (CuCl₂), cesium fluoride (CsF), tantalumfluoride (TaF₅), niobium fluoride (NbF₅), lithium bromide (LiBr),calcium bromide (CaBr₂), cesium bromide (CeBr₃), selenium bromide(SeBr₄), vanadium bromide (VBr₃), magnesium bromide (MgBr₂), bariumiodide (BaI₂), or magnesium iodide (MgI₂); or a metal chlorate such asbarium perchlorate (Ba(ClO₄)₂) or magnesium perchlorate (Mg(ClO₄)₂), butthe present invention is not limited thereto. As the moisture absorbentthat can be included in the pressure-sensitive adhesive composition, oneor at least two of the above-described materials may be used. In oneexample, when at least two of the above materials are used, the moistureabsorbent may be calcined dolomite.

Such a moisture absorbent may be controlled in a suitable size accordingto its use. In one example, an average diameter of the moistureabsorbent may be controlled to approximately 10 to 15000 nm. A moistureabsorbent having the above range of the average diameter may be easy tobe stored due to a not too high reaction speed with moisture, and mayeffectively remove moisture without damage to an element to beencapsulated.

A content of the moisture absorbent may be suitably selected withoutparticular limitation in consideration of a desired barriercharacteristic.

The pressure-sensitive adhesive composition may further include amoisture blocker when needed. The term “moisture blocker” used hereinmay refer to a material that can block or prevent migration of moistureor vapor in the film while having no or low reactivity with moisture. Asthe moisture blocker, one or at least two of clay, talc, pin-typesilica, planar silica, porous silica, zeolite, titania, and zirconia maybe used. In addition, a surface of the water blocker may be treated withan organic modifier to facilitate penetration of an organic material.Such an organic modifier, dimethyl benzyl hydrogenated tallow quaternaryammonium, dimethyl hydrogenated tallow quaternary ammonium, methyltallow bis-2-hydroxyethyl quaternary ammonium, dimethyl hydrogenatedtallow 2-ethylhexyl quaternary ammonium, dimethyl dehydrogenated tallowquaternary ammonium, or a mixture thereof may be used.

A content of the moisture blocker may be suitably selected withoutparticular limitation in consideration of a desired blockingcharacteristic.

In addition to the above-described components, various additives may beincluded in the pressure-sensitive adhesive composition according to itsuse and a process of manufacturing a pressure-sensitive adhesive filmthat will be described below. For example, the pressure-sensitiveadhesive composition may include a curable material, a crosslinkingagent, or a filler at a suitable range of content according to a desiredphysical property.

In one example, the pressure-sensitive adhesive composition of thepresent invention may have a gel content represented by Equation 1 of50% or more.

Gel content(wt %)=B/A×100  [Equation 1]

In Equation 1, A is a mass of the pressure-sensitive adhesivecomposition, and B is a dry mass of an insoluble content of thepressure-sensitive adhesive composition remaining after being dipped intoluene at 60° C. for 24 hours and filtered through a 200-mesh filter(pore size of 200 μm).

The gel content represented by Equation 1 may be 50 to 99%, 50 to 90%,50 to 80%, or 50 to 70%. That is, in the present invention, apressure-sensitive adhesive composition having an excellent moistureblocking characteristic, reliability, and an optical characteristic maybe realized, in consideration of a crosslinking structure and a suitablerange of a degree of crosslinking of the pressure-sensitive adhesivecomposition through the gel content.

In another aspect, the present invention provides a pressure-sensitiveadhesive film. The pressure-sensitive adhesive film may include apressure-sensitive adhesive layer, which may include the above-describedpressure-sensitive adhesive composition or a crosslinked productthereof. The pressure-sensitive adhesive layer may be formed in a filmor sheet. Such a pressure-sensitive adhesive layer may be used toencapsulate an organic electronic element.

In an exemplary embodiment of the present invention, thepressure-sensitive adhesive layer may be formed in a monolayer structureas described above, or may be formed in a multilayer structure includingat least two layers that will be described below. For example, thepressure-sensitive adhesive layer may include a first layer containingthe above-described pressure-sensitive adhesive composition or acrosslinked product thereof and a second layer including apressure-sensitive adhesive resin or an adhesive resin. Thepressure-sensitive adhesive resin or adhesive resin included in thesecond layer may be the same as or different from the above-describedencapsulating resin, and may be suitably selected by a conventionaltechnician according to a purpose. In addition, the first and secondlayers may or may not include a moisture absorbent.

In one example, the pressure-sensitive adhesive resin included in thesecond layer may include a curable resin including at least oneheat-curable functional group such as a glycidyl group, an isocyanategroup, a hydroxyl group, a carboxyl group, or an amide group, or anelectromagnetic wave-curable functional group such as an epoxide group,a cyclic ether group, a sulfide group, an acetal group, or a lactonegroup, which may be cured to exhibit an adhesive characteristic. Inaddition, a specific type of such a resin may be, but is not limited to,an acryl resin, a polyester resin, an isocyanate resin, or an epoxyresin.

In the present invention, as the curable resin, an aromatic oraliphatic, or linear or branched epoxy resin may be used. In oneexemplary embodiment of the present invention, an epoxy resin containingat least two functional groups and having an epoxy equivalent of 180 to1,000 g/eq may be used. When the epoxy resin having the above range ofepoxy equivalent is used, characteristics of the cured product such asadhesive performance and a glass transition temperature may beeffectively maintained. Such an epoxy resin may be one or a mixture ofat least two of a cresol novolac epoxy resin, a bisphenol A-type epoxyresin, a bisphenol A-type novolac epoxy resin, a phenol novolac epoxyresin, a tetrafunctional epoxy resin, a biphenyl-type epoxy resin, atriphenol methane-type epoxy resin, an alkyl-modified triphenol methaneepoxy resin, a naphthalene-type epoxy resin, a dicyclopentadiene-typeepoxy resin, and a dicyclopentadiene modified phenol-type epoxy resin.

In an exemplary embodiment of the present invention, the second layermay include another component such as an active energy ray-polymerizablecompound, a radical initiator, a tackifier, a moisture absorbent, amoisture blocker, a dispersing agent, or a silane compound, which may bethe same as or different from that of the first layer, in addition tothe above-described resin. In addition, the second layer may include acurable material, a curing agent, or a filler at a suitable range ofcontent according to a desired physical property.

A sequence of laminating the first and second layers is not particularlylimited, and thus the second layer may be formed on the first layer, orthe first layer may be formed on the second layer.

In one example, the pressure-sensitive adhesive film may include abarrier film on one surface of the pressure-sensitive adhesive layer.The barrier film may be formed of any material generally used in the artwithout limitation. For example, here, the barrier film may include abase layer, an organic undercoating layer, an inorganic depositionlayer, and an organic top-coating layer, and the organic top-coatinglayer may be in contact with the pressure-sensitive adhesive layer.

The pressure-sensitive adhesive film may have a water vapor transmissionrate (WVTR) measured with respect to a thickness direction of the filmwhile being manufactured in a film having a thickness of 10 μm of 50,40, 30, 20, or 10 g/m²·day or less at 100° F. and a relative humidity of100%. By controlling a composition or crosslinking condition of apressure-sensitive adhesive layer including a pressure-sensitiveadhesive composition to have such a WVTR, an encapsulation orcapsulation structure which can stably protect an element by effectivelyblocking moisture or oxygen penetrated from an external environment whenbeing applied to an encapsulation or capsulation structure of anelectronic device may be realized. The lower WVTR, the better moisturebarrierability, and therefore the lower limit of the WVTR may be, but isnot particularly limited to, 0 g/m²·day.

In addition, the pressure-sensitive adhesive film may have an excellentlight transmittance with respect to a visible-ray region. In oneexample, the pressure-sensitive adhesive film of the present inventionmay have a light transmittance of 88%, 89%, or 90% or more with respectto the visible-ray region. In addition, the pressure-sensitive adhesivefilm of the present invention may exhibit a low haze with the excellentlight transmittance. In one example, the pressure-sensitive adhesivefilm may have a haze of 3%, 2.8%, 2.5%, 2.3%, 2.2%, or 2.0% or less. Thepressure-sensitive adhesive composition according to the presentinvention may minimize the change in a haze.

The pressure-sensitive adhesive film may further include a base film orrelease film (hereinafter, can be referred to as a “first film”), andhave a structure in which the pressure-sensitive adhesive layer isformed on the base or release film. The structure may further include abase or release film formed on the pressure-sensitive adhesive layer(hereinafter, can be referred to as a “second film”).

FIGS. 1 and 2 are cross-sectional views of exemplary pressure-sensitiveadhesive films.

The pressure-sensitive adhesive film 1, as shown in FIG. 1, may includea pressure-sensitive adhesive layer 11 formed on a base or release film12. Another exemplary pressure-sensitive adhesive film 2, as shown inFIG. 2, may further include a base or release film 21 formed on thepressure-sensitive adhesive layer 11. Although not shown in FIGS. 1 and2, the pressure-sensitive adhesive film may also have thepressure-sensitive adhesive composition without a supporting base suchas a base or release film, and therefore have a structure only includinga pressure-sensitive adhesive layer formed in a film or sheetmaintaining a solid phase or a semi-solid phase at room temperature, ora structure in which a pressure-sensitive adhesive layer is formed onboth surfaces of one base or release film.

A specific type of the first film is not particularly limited. As thefirst film, for example, a plastic film may be used. The first film maybe a polyethyleneterephthalate film, a polytetrafluoroethylene film, apolyethylene film, a polypropylene film, a polybutene film, apolybutadiene film, a vinyl chloride copolymer film, a polyurethanefilm, an ethylene-vinyl acetate film, an ethylene-propylene copolymerfilm, an ethylene-ethyl acrylate copolymer film, an ethylene-methylacrylate copolymer film, or a polyimide film.

When the first film is a release film, suitable release treatment may beperformed on one or both surfaces of such a plastic film. As a releasingagent used for release treatment, an alkyd-based releasing agent, asilicon-based releasing agent, a fluorine-based releasing agent, anfluorinated ester-based releasing agent, a polyolefin-based releasingagent, or a wax-based releasing agent may be used. In consideration ofheat resistance, an alkyd-based releasing agent, a silicon-basedreleasing agent, or a fluorine-based releasing agent among the aboveexamples may be conventionally used, but the present invention is notlimited thereto.

As the first film, for example, a plastic film in which a gas barrierlayer is formed on a top or side surface of a base may be used. Such afilm may directly constitute, for example, a substrate of an organicelectronic device to be used for realizing a flexible device.

A type of the second film is not particularly limited, either. Forexample, as the second film, within the category of the first filmlisted above, one that is the same as or different from the first filmmay be used.

A thickness of the first or second film is not particularly limited. Inone example, the thickness of the first film may be approximately 50 to500 or 100 to 200 μm. In such a range, a process of preparing ormanufacturing a pressure-sensitive adhesive or an organic electronicdevice may be effectively automated, and advantageous effects in termsof economic feasibility may be achieved.

The thickness of the second film is not particularly limited, either.For example, the thickness of the second film may be the same as, orrelatively smaller or larger than that of the first film.

The pressure-sensitive adhesive layer of the pressure-sensitive adhesivefilm includes the pressure-sensitive adhesive composition, and is formedin a film or sheet. In the pressure-sensitive adhesive layer, thepressure-sensitive adhesive composition may be in a crosslinked ornon-crosslinked state. The pressure-sensitive adhesive layer may be in asolid or semi-solid phase at room temperature. The curablepressure-sensitive adhesive resin included in the solid or semi-solidpressure-sensitive adhesive layer may be in a non-crosslinked state.Such a pressure-sensitive adhesive resin may form a crosslinkedstructure in an encapsulation structure of an organic electronicelement, which will be described below.

A thickness of the pressure-sensitive adhesive layer is not particularlylimited, and may be suitably selected in consideration of its uses. Forexample, the pressure-sensitive adhesive layer may have a thickness ofapproximately 5 to 200 μm. The thickness of the pressure-sensitiveadhesive layer may be controlled in consideration of, for example,embeddability when being used as an encapsulant of an organic electronicelement and processability or economic feasibility.

In still another aspect, the present invention provides a method ofmanufacturing a pressure-sensitive adhesive film. The exemplarypressure-sensitive adhesive film may be manufactured by plasticizing thepressure-sensitive adhesive composition in a film or sheet.

In one example, the method may include applying a coating solutionincluding the pressure-sensitive adhesive composition on a base orrelease film in a sheet or film, and drying the applied coatingsolution. The method may further include adhering an additional base orrelease film to the dried coating solution.

The coating solution including the pressure-sensitive adhesivecomposition may be prepared by, for example, dissolving or dispersingcomponents of each pressure-sensitive adhesive composition describedabove in a suitable solvent. In one example, the pressure-sensitiveadhesive composition may be prepared by dissolving or dispersing themoisture absorbent, blocker, or filler in a solvent when needed,grinding the resulting product, and mixing the moisture absorbent,blocker, or filler with an encapsulating resin.

A type of a solvent used in preparation of the coating solution is notparticularly limited. However, when time to dry the solvent is too long,or it is necessary to dry the solvent at a high temperature, there mayhave some problems in workability or durability of a pressure-sensitiveadhesive film. For this reason, a solvent having a volatile temperatureof 150° C. or less may be used. In consideration of film moldability, asmall amount of the solvent having the above range of the volatiletemperature may be used. The solvent may be, but is not limited to, oneor at least two of methylethylketone (MEK), acetone, toluene, dimethylformamide (DMF), methyl cellosolve (MCS), tetrahydrofuran (THF), xylene,and N-methylpyrrolidone (NMP).

A method of applying the coating solution to the base or release filmmay be, but is not particularly limited to, a known coating method suchas knife coating, roll coating, spray coating, gravure coating, curtaincoating, comma coating, or lip coating.

The applied coating solution may be dried to volatilize the solvent,thereby forming a pressure-sensitive adhesive layer. The drying may beperformed, for example, at 70 to 150° C. for 1 to 10 minutes. The dryingcondition may be changed in consideration of a type of the used solvent.

After drying, an additional base or release film may be formed on thepressure-sensitive adhesive layer.

In yet another aspect, the present invention provides a product forencapsulating an organic electronic device. The product forencapsulating an organic electronic device may include a substrate; anorganic electronic element formed on the substrate; and apressure-sensitive adhesive film encapsulating an entire surface, forexample, top and side surfaces of the organic electronic element. Thepressure-sensitive adhesive film may include a pressure-sensitiveadhesive layer containing a pressure-sensitive adhesive composition in acrosslinked state. The product for encapsulating an organic electronicdevice may further include a cover substrate formed on a top surface ofthe pressure-sensitive adhesive layer.

Here, the organic electronic element may be, for example, an organiclight emitting element.

In yet another aspect, the present invention provides a method ofmanufacturing an organic electronic device. The product forencapsulating an organic electronic device may be manufactured using,for example, the pressure-sensitive adhesive film.

The pressure-sensitive adhesive layer may be formed as an encapsulatinglayer for a structure exhibiting excellent moisture barrier property andoptical property in the organic electronic device, efficiently fixingand supporting the substrate and a cover substrate.

In addition, the pressure-sensitive adhesive layer may exhibit excellenttransparency, and may be stable regardless of a type of the organicelectronic device, for example, a top-emissive or bottom-emissiveorganic electronic device.

The term “encapsulating layer” used herein may refer to apressure-sensitive adhesive layer covering top and side surfaces of theorganic electronic element.

FIG. 3 is a schematic diagram of an exemplary organic electronic devicein which an organic electronic element is an organic light emittingelement.

To manufacture the organic electronic device, for example, applying theabove-described pressure-sensitive adhesive film to the substrate onwhich the organic electronic element is formed to cover the organicelectronic element; and curing the pressure-sensitive adhesive film maybe included.

The term “curing” used herein may refer to preparing apressure-sensitive adhesive by forming the pressure-sensitive adhesivecomposition of the present invention to have a crosslinking structurethrough heating or UV irradiation.

Specifically, an organic electronic element 32 may be formed by forminga transparent electrode on a glass or polymer film 31 used as asubstrate by a method such as vacuum deposition or sputtering, forminglayers of emissive organic materials, composed of, for example, a holetransport layer, an emitting layer, and an electron transport layer onthe transparent electrode, and further forming an electrode layerthereon. Subsequently, a pressure-sensitive adhesive layer of thepressure-sensitive adhesive film is disposed to cover an entire surfaceof the organic electronic element 32 of the substrate 31 subjected tothe above-described process.

Subsequently, an encapsulating layer may be formed by compressing thepressure-sensitive adhesive layer on the organic electronic elementusing a laminator while heating the pressure-sensitive adhesive layer toprovide mobility, and crosslinking a resin in the pressure-sensitiveadhesive layer.

In one example, a pressure-sensitive adhesive layer 33 disposed to coveran entire surface of the organic electronic element 32 may be previouslytransferred to a cover substrate 34 such as a glass or a polymer film.The transfer of the pressure-sensitive adhesive layer to the coversubstrate 34 may be performed using a vacuum press or vacuum laminatorwhile being heated in a state in which the pressure-sensitive adhesivelayer is in contact with the cover substrate 34, after peeling a firstor second film from the pressure-sensitive adhesive film. When thepressure-sensitive adhesive includes a heat-curable pressure-sensitiveadhesive resin and a curing reaction is excessively performed during theprocess, a cohesive strength or pressure-sensitive adhesive strength ofthe encapsulating layer is probably reduced. Therefore, a processtemperature may be controlled to approximately 100° C. or less, and aprocess time may be controlled within 5 minutes.

An encapsulating layer may be formed by disposing the cover substrate 34to which the pressure-sensitive adhesive is transferred on the organicelectronic element 32, and performing the heat compression process.

The encapsulating layer may be formed by curing the pressure-sensitiveadhesive layer 33. The curing process may be performed in a suitableheating chamber or UV chamber, for example, according to a method ofcuring a curable pressure-sensitive adhesive resin. A heating conditionor a condition of irradiating an active energy ray maybe suitablyselected in consideration of stability of the organic electronic elementand curability of the pressure-sensitive adhesive resin, and to increasea compression efficiency, autoclaving with co-application of heat andpressure may be performed.

Here, one example of the method of manufacturing an organic electronicdevice is described, but the organic electronic device may bemanufactured by a different method. For example, the manufacture of thedevice is performed by the above-described method, but a sequence orcondition of the process may be changed. For example, the encapsulatinglayer may be formed by previously transferring the pressure-sensitiveadhesive layer to the substrate 31, not to the cover substrate 34, andperforming a curing process while the cover substrate 34 is laminated.

Effects

The present invention can provides a pressure-sensitive adhesivecomposition that can effectively prevent moisture or oxygen added to anorganic electronic device from an external environment, and exhibitreliability under harsh conditions such as high temperature and highhumidity and excellent optical characteristics, and a pressure-sensitiveadhesive film including the same.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are cross-sectional views of pressure-sensitive adhesivefilms according to exemplary embodiments of the present invention; and

FIG. 3 is a cross-sectional view of an encapsulating product for anorganic electronic device according to an exemplary embodiment of thepresent invention.

DESCRIPTION OF REFERENCE NUMERALS

-   -   1, 2: pressure-sensitive adhesive film    -   11: pressure-sensitive adhesive layer    -   12: first film    -   21: second film    -   3: organic electronic device    -   31: substrate    -   32: organic electronic element    -   33: pressure-sensitive adhesive layer or encapsulating layer    -   34: cover substrate

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, the present invention will be described in detail withreference to Examples and Comparative Examples, but the scope of thepresent invention is not limited to the following Examples.

Example 1

A coating solution was prepared by adding 70 g of a butyl rubber (Br268,EXXON) as an encapsulating resin, 30 g of a hydrogenated DCPD-basedtackifier resin (SU-90, Kolon) as a tackifier, 20 g of tricyclodecanedimethanol diacrylate (SR833S, Sartomer) as an active energyray-polymerizable compound, and 1 g of2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure651, Ciba) as a radicalinitiator, and diluting the mixture in toluene to have a solid contentof approximately 15 wt %.

The prepared solution was coated on a released surface of release PET,and dried in an oven at 100° C. for 15 minutes, thereby manufacturing apressure-sensitive adhesive film including a pressure-sensitive adhesivelayer having a thickness of 50 μm. Physical properties of the samplewere measured after UV rays were irradiated at 2 J/cm² on themanufactured film.

Example 2

A pressure-sensitive adhesive film was manufactured by the same methodas described in Example 1, except that 1,8-octanediol diacrylate wasused as anactive energy ray-polymerizable compound, instead oftricyclodecane dimethanol diacrylate.

Example 3

A pressure-sensitive adhesive film was manufactured by the same methodas described in Example 1, except that trimethylolpropane triacrylatewas used as an active energy ray-polymerizable compound, instead oftricyclodecane dimethanol diacrylate.

Comparative Example 1

A pressure-sensitive adhesive film was manufactured by the same methodas described in Example 1, except that 70 g of polyisobutylene (BASF,B80) was used as an encapsulating resin.

Comparative Example 2

A pressure-sensitive adhesive film was manufactured by the same methodas described in Example 1, except that dipropylene glycol diacrylate wasused as an active energy ray-polymerizable compound, instead oftricyclodecane dimethanol diacrylate.

Comparative Example 3

A pressure-sensitive adhesive film was manufactured by the same methodas described in Example 2, except that octyl acrylate was used as anactive energy ray-polymerizable compound, instead of 1,8-octanedioldiacrylate.

Comparative Example 4

A pressure-sensitive adhesive film was manufactured by the same methodas described in Example 1, except that dipentaerythritol hexaacrylatewas used as an active energy ray-polymerizable compound, instead oftricyclodecane dimethanol diacrylate.

Comparative Example 5

A pressure-sensitive adhesive film was manufactured by the same methodas described in Example 1, except that polybutadiene dimethacrylate wasused as the active energy ray-polymerizable compound, instead oftricyclodecane dimethanol diacrylate.

Hereinafter, physical properties were evaluated by the following methodsin the Examples and Comparative Examples.

1. Get Content

Gel content(wt %)=B/A×100

Here, A is a mass of the pressure-sensitive adhesive composition, and Bis a dry mass of an insoluble content of the pressure-sensitive adhesivecomposition remaining after being dipped in toluene at 60° C. for 24hours and filtered through a 200-mesh filter (pore size: 200 μm).

2. Evaluation of Reliability

A sample was prepared by laminating the film manufactured in Example orComparative Example on a barrier film (serving as a cover substrate),laminating the resulting product on a substrate, and pressure andheat-compressing the resulting product using an autoclave at 50° C. and5 atm. Afterward, the sample was maintained in a constant temperatureand constant humidity chamber at 85° C. and a relative humidity of 85%for approximately 500 hours, and it was observed whether lifting,bubbles, or hazes were generated at an interface between a glasssubstrate and a pressure-sensitive adhesive layer. When being viewedwith the naked eye, at the interface between the glass substrate and thepressure-sensitive adhesive layer, if at least one lifting, bubble, orhaze was generated, it was represented as X, and if no lifting, bubble,or haze was generated, it was represented as O.

3. Measurement of Light Transmittance and Haze

A light transmittance of the pressure-sensitive adhesive filmmanufactured as described above was measured at 550 nm using a UV-VISspectrometer, and a haze of the pressure-sensitive adhesive film wasmeasured using a haze meter according to a standard test method of JISK7105.

TABLE 1 High temperature & high Light Gel humidity reliabilitytransmittance Haze % 85° C., 85% RH % — Example 1 74 O 90 0.5 Example 253 O 90 1.9 Example 3 57 O 90 0.9 Comparative 0 X 90 0.4 Example 1Comparative 0 X 90 0.4 Example 2 Comparative 0 X 90 0.4 Example 3Comparative 0 X 88 9.8 Example 4 Comparative 0 X 89 0.5 Example 5

What is claimed is:
 1. A pressure-sensitive adhesive composition,comprising: an encapsulating resin comprising a copolymer of a diene andan olefin-based compound having one carbon-carbon double bond; and amultifunctional active energy ray-polymerizable compound satisfyingFormula 1:

wherein R₁ is hydrogen or an alkyl group having 1 to 4 carbon atoms, nis an integer of 2 or more, and X is a residue induced from a linear,branched, or cyclic alkyl group having 3 to 30 carbon atoms.
 2. Thecomposition according to claim 1, which has a haze of 3% or less whilebeing formed in a film.
 3. The composition according to claim 1, whereinthe active energy ray-polymerizable compound is included at 5 to 30parts by weight relative to 100 parts by weight of the encapsulatingresin.
 4. The composition according to claim 1, further comprising: atackifier.
 5. The composition according to claim 4, wherein thetackifier is a hydrogenated cyclic olefin-based polymer.
 6. Thecomposition according to claim 4, wherein the tackifier is included at 5to 100 parts by weight relative to 100 parts by weight of theencapsulating resin.
 7. The composition according to claim 1, furthercomprising: a radical initiator.
 8. The composition according to claim7, wherein the radical initiator is a photoinitiator or a thermalinitiator.
 9. The composition according to claim 7, wherein the radicalinitiator is included at 0.2 to 20 parts by weight relative to 100 partsby weight of the active energy ray-polymerizable compound.
 10. Thecomposition according to claim 1, further comprising: a moistureabsorbent.
 11. A pressure-sensitive adhesive film, comprising: apressure-sensitive adhesive layer comprising the pressure-sensitiveadhesive composition of claim 1 or a crosslinked product thereof. 12.The film according to claim 11, wherein the pressure-sensitive adhesivelayer comprises a first layer having the pressure-sensitive adhesivecomposition of claim 1 or a crosslinked product thereof and a secondlayer having a pressure-sensitive adhesive resin or an adhesive resin.13. The film according to claim 11, which has a water vapor transmissionrate in a thickness direction of 50 g/m²·day or less when manufacturedto have a thickness of 100 μm.
 14. The film according to claim 11, whichhas a light transmittance of 90% or more with respect to a visible-rayregion.
 15. The film according to claim 11, which has a haze of 3% orless.
 16. A product for encapsulating an organic electronic device,comprising: a substrate; an organic electronic element formed on thesubstrate; and the pressure-sensitive adhesive film according to claim11 to encapsulate the organic electronic element.
 17. A method ofmanufacturing an organic electronic device, comprising: applying thepressure-sensitive adhesive film of claim 11 to a substrate on which anorganic electronic element is formed to cover the organic electronicelement; and curing the pressure-sensitive adhesive film.